| Project/Area Number |
11640652
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物生理
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
MATSUURA Katsumi Tokyo Metropolitan University. Graduate School of Science, Associate Professor, 理学研究科, 助教授 (30181689)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Photosynthesis / Photosynthetic Bacteria / Photosynthetic Reaction Center / Cytochrome / Protein / Molecular Evolution / Electron Transfer / 電子移動 / 反応中心 |
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| Research Abstract |
Protein-surface amino acids on the photosynthetic reaction center complex were examined in terms of the role of each amino acid in the protein-protein interaction. The cytochrome subunit bound to the reaction center complex of purple bacteria was used. The cytochrome subunit has a good genetic system, constructed by this investigator's group, to introduce site-directed mutagenesis. The conservation and changes of amino acids during evolution and their relation to environmental changes were also studied. During the two-year investigation, following results were obtained.
1. On the site of electron input to the cytochrome subunit of the reaction center from solubule electron donors, an acidic amino acid were changed to hydrophobic amino acid in R.gelatinosus.
2. In R.sulfidophilum, the number of bound hemes in the cytochrome subunit was 3 instead of normal number of 4. This was considered as results of natural mutation. Amino acids which are important for heme binding have been lost for the forth heme in the subunit.
3. The gene for the cytochrome subunit of B.viridis was successfully introduced to the cells of R.gelatinosus. Using this hybrid system, we can now introduce site-directed mutagenesis to the protein which structure has been finely solved.
4. In B.viridis, acidic amino acids are solely important for the interaction with electron donors, but in R.gelatinosus hydrophobic amino acids are also important.
5. With relation to the evolution of photosynthetic organisms, several pieces of new information about the oxidative environment adaptation of the gene expression and light-energy transfer.
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